Atmospheric River Party!

TL;DR: 

A series of remnant Atmospheric Rivers will bring sub-tropical moisture to Northern Utah beginning later tonight. Above-average chances for precipitation are expected for at least the next two weeks with models hinting at a wet pattern remaining through the end of the month!

Nowcast: 

As of 1pm MST, you can expect relatively warm temperatures and windy conditions with partly cloudy skies trending to overcast through the end of the day. Temperatures currently range from 36F near the base of Deer Valley at 6500' to 30F near the base of Brighton at 8800' to 19F on Mount Baldy at 11000'. Some the more wind-prone lifts may see wind holds through the end of the day with Great Western Express at Brighton already closed. 

Webcam at the top of the Great Western Express lift socked in with low clouds. Image courtesy of Brighton Resort.

Short-term Forecast

The remnants of a Scale 4 Atmospheric River and associated bomb cyclone will make their way inland today with precipitation starting late in the evening. Some pre-frontal snow showers may occur before the frontal passage at 4am 1/6 with totals being in the 2-4 inch range for the Upper Cottonwoods before 4am. After the frontal passage, moderate snowfall will continue through Friday afternoon with the potential for a "Goldilocks" storm when all is said and done. This is completely subjective but generally, goldilocks storms are in the 12-18 inch range with snow densities decreasing as the storm wears on (also called right-side-up snowfall). Enough to cover old tracks, but not so much that you can't make good turns.

GFS Wind Speed, Gust, and Direction for Mt. Baldy (11,000'). Frontal passages can be identified by changes in wind direction - Cold fronts in this part of Utah generally shift from Southerly pre-frontal to Westerly/Northwesterly post-frontal, as seen here around 4am Friday as indicated with the green plusses representing wind direction. Image courtesy the University of Utah, Department of Atmospheric Sciences.

This will be a much more typical Wasatch storm than what we have seen in recent days, with cold frontal passage bringing Northwesterly orographic (upslope, terrain-enhanced) precipitation, favoring the typical spots in Upper Little Cottonwood Canyon.

Snow Forecast through 12am Saturday 1/7

Big Cottonwood (Solitude and Brighton) - 8 to 14 inches

Little Cottonwood (Alta and Snowbird) - 12 to 16 inches

Park City and Deer Valley - 4 to 6 inches for bases (~7000ft), 8 to 12 inches for upper elevations (~9000ft)

Weeks 3-4 Precipitation Outlook shows above average chances of precipitation remaining for the period valid January 14-27, 2023. Image courtesy of the Climate Prediction Center. 

Long-term Forecast

Looking down the road, a series of atmospheric rivers will continue to make landfall in Northern California, with the remnant moisture making its way to Utah. Saturday and Sunday will be dry before another significant storm begins Monday afternoon. Stay tuned to our website or @utahskiweather on Twitter for posts in the coming days giving a more in-depth discussion of that upcoming storm. Even further into the future, the NOAA Climate Prediction Center is forecasting above average chances of precipitation persisting through the end of the month. January 2023 could very well go down in Utah ski history as one to remember. 

One more graphic from the Climate Prediction Center because it looks too good to resist. Slight chance of heavy snow risk from January 12 to January 18, from this experimental product.

If you plan to travel in the backcountry ensure you are properly equipped and know before you go. For all things avalanche and the full avalanche forecast head over to our friends at the Utah Avalanche Center.